In a conventional radiation detection apparatus in a radiation tomography apparatus, a collimator and a detector element array are generally attached to each other as individual components (for example, see Abstract in Patent Document 1 and the like). However, since in recent years coverage in a slice direction is extended, and the collimator arcuately arranged facing a radiation source may lead to better control of image quality degradation, a construction having the collimator integrated with the detector element array is becoming mainstream. In such a construction, the collimator and detector element array are generally adhesively secured by an adhesive.